How severe is CVE-2020-15500?

CVE-2020-15500 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2020-15500?

CVE-2020-15500 affects the following packages: tileserver-gl (npm). Ecosystems affected: npm.

How do I fix CVE-2020-15500?

Update tileserver-gl to 3.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15500 is resolved across your whole dependency graph.

How do I detect CVE-2020-15500 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tileserver-gl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-15500 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2020-15500 actively exploited in the wild?

Yes. There are 3 known exploit references for CVE-2020-15500, including 1 documented proof-of-concept exploit on Exploit-DB and 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-15500?

CVE-2020-15500 has an EPSS (Exploit Prediction Scoring System) score of 12.2%, placing it in the 96th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

What type of vulnerability is CVE-2020-15500?

CVE-2020-15500 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Is there exploit tooling available for CVE-2020-15500?

A Nuclei detection template exists for CVE-2020-15500, meaning automated scanners can fingerprint it. Public exploit tooling significantly increases real-world risk — prioritize patching and ensure detection coverage. Exploit tooling should only ever be used in isolated, authorized testing environments.

When was CVE-2020-15500 published, and has it been updated?

CVE-2020-15500 was published on July 1, 2020 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

MEDIUM severity

CVE-2020-15500 — tileserver-gl

MEDIUMFix: maptiler/tileserver-gl@10431d7

CVE-2020-15500 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in tileserver-gl. 3 public exploit references exist, so weaponization risk is real. A fix is available for tileserver-gl — see the affected versions and patch details below.

Cross-site scripting in TileServer GL

Also known asGHSA-3fr8-mwpp-8h9p

Published

Jul 1, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

3 known

Exploitation data as of Oct 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

12.2%probability of exploitation in next 30 days

Moderate Risk0.00%

Lower risk than most CVEs96th percentile — riskier than 96% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2020-15500 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

tileserver-glnpm

855downloads / week

Description

An issue was discovered in server.js in TileServer GL through 3.0.0. The content of the key GET parameter is reflected unsanitized in an HTTP response for the application's main page, causing reflected XSS.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`tileserver-gl`	all versions	3.1.0`npm install tileserver-gl@3.1.0`

Affected Products

1 product · 1 configurations

Application

tileservergltileserver

≤ 3.0.0

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-49771webappsmultiple

Tileserver-gl 3.0.0 - 'key' Reflected Cross-Site Scripting (XSS)

by Akash Chathoth · Apr 15, 2021

Exploit-DB Source

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for tileserver-gl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update tileserver-gl to 3.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15500 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

How to detect CVE-2020-15500

A community-maintained Nuclei template exists for this CVE. You can scan for it directly:

nuclei -id cve-2020-15500 -u https://target

Template: TileServer GL <=3.0.0 - Cross-Site Scripting
Severity: medium
Impact: Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to potential data theft, session hijacking, or defacement.
Remediation: Upgrade TileServer GL to a version higher than 3.0.0 or apply the vendor-provided patch to fix the XSS vulnerability.

Template by ProjectDiscovery nuclei-templates (Akash.C), MIT licensed. View the full template. Scan only systems you are authorised to test.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-15500 in your dependencies?

Find it across npm, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

CWE Classification

CWE-79Cross-site Scripting (XSS)

Weaponization

OpenSSF Scorecard

Package health score

tileserver-gl

6.5/10

Code-Review3/10

Maintained10/10

Branch-ProtectionN/A

Assessed Oct 5, 2026

Timeline

Disclosed

Jul 1, 2020

First exploit

Apr 15, 2021

Last updated

Jul 8, 2026

Identifiers

CVE-2020-15500

GHSA-3fr8-mwpp-8h9p

References

Advisorynvd.nist.gov Webgithub.com Packagegithub.com Evidencepacketstormsecurity.com Evidencegithub.com

Related vulnerabilities

This CVE is medium severity; 8 of 8 other CVEs with CWE-79 are rated as high or higher (top: high).

CVE-2026-91127CVE-2026-77606CVE-2026-84992CVE-2026-77608CVE-2026-77607GHSA-9rcc-pmj8-ffhrCVE-2026-77616CVE-2025-61682Browse all CWE-79

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 8, 2026